Niantic engineers are reportedly working on new functions, among them features such as a player versus player function, player trading and co-operative raids, according to the Birmingham Mail.

Pokemon Go became a worldwide sensation last summer as tens of millions of fans downloaded the app. In Pokemon Go, players move around locations capturing animated creatures on smartphones and other mobile devices.

Comicbook.com said in an interview with Brazilian newspaper O Globo, that a Niantic official seemed to confirm that Pokemon Go fans would be seeing Legendary Pokemon and a lot more this summer. Interest in Pokemon Go fell off as the summer drew to a close, and the challenge for Niantic is to sustain the game’s popularity. Niantic also has some technical issues to iron out, as the unexpected popularity of the game last summer overwhelmed its ability to handle the surge in interest.

Niantic, a spin-off of Google parent Alphabet Inc. (NASDAQ: GOOGL), is worth more than $3.65 billion, according to a research note sent to investors by analysts at Citibank, according to Quartz. Its app was launched July 6 and has vaulted it to the top of global app stores.